Orca whales are cetaceans, a
large group of approximately 80 kinds of whales, dolphins, and
porpoises. The largest member of the dolphin family (females can grow as
large as 23 feet in length, while males can reach 32 feet), orca whales
have highly developed brains, and like all dolphins, use sophisticated
biological sonar called echolocation, to communicate with one another.
When the Southern Resident Community whales arrive in Haro Strait on the
southeast shores of Vancouver Island, they “announce” their arrival to
other whales already in the area with their highly developed vocal
activity.
Types of Orcas
Orca
whales are divided into three separate categories based upon
geographical location and behavior. It is speculated that these three
distinct groups of orcas in the Pacific Northwest may be the result of
food preference and availability.
Resident
Orcas tend to have distinct and stable migration patterns and family
structures, while Transient Orca Whales are more loosely organized. It
is estimated that there are approximately 450 Transient Orca Whales
living along the western North American seaboard from Mexico to the
Bering Sea. Little is currently known about the third category, Offshore
Orcas, although they are being actively studied by scientists.
Discovered in 1991, the Offshore Orcas are most commonly seen 15 to 25
miles out at sea off Vancouver Island and the Queen Charlotte Islands.
It is possible that this third category of whales is the ancestral
population of the Northern and or the Southern Resident orca whales.
Social Structure
Orca
whales generally live in groups known as pods, which are comprised of
two or more females, calves, one or more males, and juveniles. These
stable, matrilineal pods of orcas often consist of a mother, her
offspring, and several generations of family members who travel
together. Some offspring stay with their mother for life. This type of
familial structured pod has been consistently observed in the Pacific
Northwest. While all pods share common sounds, each pod also has its own
distinctive sound.
Foraging
With
46 to 50 conical shaped teeth that point slightly inwards and
backwards, the orca is well adapted for hunting. While resident orca
whales tend to feed on fish species such as herring or salmon, transient
whales eat a variety of animals including smaller whales, penguins,
porpoises, harbour seals, sea lions, squid and sharks. Orcas generally
forage individually, although it is thought by scientists that a
coordinated method of group hunting probably occurs.
Breeding
Although
very little is understood about the orca's breeding habits, newborn
calves have been observed throughout the year, indicating no particular
breeding season. Orcas are considered to be sexually mature between the
ages of 10 and 18 years of age, with females believed to be
reproductively active into their 40's. The gestation period for an orca
is approximately between 13 to 17 months, and a newborn calf is
generally about 6-7 feet long, and weighs approximately 400 pounds.
Resting
When resting, orca whales generally maintain a slow swimming speed (2 knots or less), and synchronize their breathing with other whales within their social group. They also rest while laying almost motionless on the surface of the water. During these very quiet rest periods, orcas emit just a few discrete sounds, and scientists believe that one group member may remain more attentive than the remaining pod.
In
2016 and 2017 we will be running two different types of tours that incorporate
whale photography. One is a wildlife workshop, the other a tour of the
west and east coast of Vancouver Island. Please visit our Canadian Workshop page to see all our workshops and tours in Canada. http://northof49photography.com/photo-workshops
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